Scored a Laserscope YAG!

This is what everyone loves to hear :-)

Where exactly does the beam shoot out from? KIDDING!

Picked up a laserscope YAG recently. It's a 800 series, built in heat exchanger.

Did some research before hand and have continued to do more research on them.

I'm a good ways from trying to fire it up.

Been reading the documentation on ?DJ Allens? site. He has what appears to be the class manual from a service tech class on the units. Very very very informative. Same with the video on youtube.

Has anyone attempted to build a microcontroller based computer replacement for these? I saw the video on youtube where someone was using the project box style switch boxes, and a meter. Seems like a good fit for a controller. I'd be willing to collab on this and share the results.

The earlier project on here where someone split the PSU / cooling / head apart seems ripe. Holy HELL is the thing heavy. I guess I should of expected it, but yea. We laid it down in a pick up and to get it out we had to tie rope to the wheels -- then to a pole and drive away to slide it out of the truck :-) I was eyeballing it for places to shed weight.

I've been researching DI water. DI water is required, correct? Not distilled? I'm going to poke around locally and see if there is a source for DI water.

I assume that a series of peltier coolers wouldn't have enough umph to chill a water loop instead of the radiator. 5000W is ~17,000 btu/hr. Hmmm peltiers are only 100-300 btu it seems. I assume the lamp runs solid and the only pulse is a result of the q-switch gating the output. 17,000 btu seems way more than a radiator could dissipate so my number is way off there I assume.

I looked to see if there are any newer more modern power supplies that are smaller for the lamp, but nothing jumped out.

Also going to research safety eyewear that matches the system.

Neat machine though!

Are conversions still in use much in the light show world or is everyone diode?

Heya tel -

Some 'unsolicited food for thought'.. :p

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Originally Posted by telmnstr

..I'm a good ways from trying to fire it up.

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Yes, please. :) You need pulsed-laser system safety fundamentals session, first and foremost. This is *not* a 'learn by trial and error' kind-of laser system. Even if you didn't 'mind being blind', the 'typical' first-temptation is 'show the new hot rod off to-friends', etc, and as the saying goes, 'friends don't let friends blind other friends'. :)

So yea - we needa tawk... :) I'd happily offer a 'discussion-session', but I am booked-solid till after July 6th (..I'm only 'here', right now, waiting for 3D-renderings / video to crunch, etc..) Check with 'P'fessor Steve' (mixedgas) He (may) have more time avail, than I, meantime...

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Originally Posted by telmnstr

Been reading the documentation on...

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..Mk, yeah... (insert facepalm) Don't believe everything you can 'glean off the interwebz'.. Much of that information is *incorrect*, or, at the very-least, not 'optimal'.. Sure, the 'OEM Service manuals' are "helpful" and good to have, great, fine. But, other info is just flat-out wrong. I can't tell you how many 'help calls' I've gotten from people, saying 'well, I followed the info on that site, and my stuff aren't-working.. helllp!..' ... You may think '...yeah, but you could 'learn a lot from a dummy'.. :p but, this is not one of those cases.. :cool: So, yeah... training, *first*, then, help towards 'proper conversion path'... Which will also-be based on your 'intentions' for-use (ie: public-shows, of any-sort, v/o a Var, etc.. = Ø help. :cool:

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Originally Posted by telmnstr

Has anyone attempted to build a microcontroller based computer replacement for these?...

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Yes, the 'Godfather of Green', Laserman532, *pioneered* it, other Co's have built very-respectable versions (ie: 'StellaRay'..) and there are even PL-members that have done-so... Speaking for-myself / Co. tho, I have always felt more 'comfy' flinging-around that kind of power, with 'dumb'-old hard-wired keyswitches and toggles...

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Originally Posted by telmnstr

I was eyeballing it for places to shed weight.

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There's a (useless for anything but surgery-stable input-power..) 150# 1:1 transformer in the base, but.. like I said.. 'baby-steps'.. :)

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Originally Posted by telmnstr

DI water is required, correct? Not distilled?

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Nope, not-needed. But the 'correct' answer (..and 'why' it is correct..) will be given after 'class'.. :p

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Originally Posted by telmnstr

5000W is ...

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...4.5kW is min. and the *entire* cooling-loop must be maintained as-designed.. As-to 'why', again, is related to the above-answer, yours for the 'price of admission'.. :p

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Originally Posted by telmnstr

Also going to research safety eyewear that matches the system.

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Also, something better-covered 'in class'.. Eyeware - by-itself - can lead to a 'false-sense of security', and actually 'create' other hazards... Not to say they are 'not needed', but.. there's a 'seasoned-approach' to working with these systems, that just 'buying a pair of 1064/532 glasses' does-not teach...

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Originally Posted by telmnstr

Are conversions still in use much in the light show world or is everyone diode?

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Sometimes, there's just nothing-else that will-do... And, in the not-too-distant future, you are (imho..) going to see a 'resurgence of use' of these, when a certain 'augmenting product' hits the market... Some of the biggest Sho co's still maintain an arsenal of them, because in certain-circumstances / applications, there's just (still..) no 'topping' them.. And there's a -specific-reason-, beyond just 'sheer-power' / color...

Anyhoo, please take this all in the 'spirit in-which it is intended' - to-help :cool: But, please also do-know that safely, reliably, and responsibly-operating these systems is *not* just a case of 'all you need is a dollar and a key'... :p Much, much more to making a success of these than 'the score'...

Talk to you more, asap.. :cool:
j

Very cool. I'm aware that when driven in q-switch mode the output technically looks like something of a saw wave, and power measurements will only show an average of that.

As far as replacement controller, I'd still have a hardware keyswitch to turn the whole thing off, then a second keyswitch for the q-switch driver if that can be done.

The only manuals I've really looked at were the OEM service manuals and some of the schematics for the bypass controller type stuff.
I read a few old threads that I could find with information (such as early 700s have unreliable/failure prone power supplies.)

My first use is basically a static shot into the sky during an event I help run, and I've already talked to the FAA trying to figure out if we had any special cases here since we have two airports that are commercial, then a few that are .mil. They said all they need is the form. Of course my side needs variance as well. And I recently found out from another group in the area they were denied by the FAA (but they were sitting under a flight path I think.)

Interesting regarding the 1:1 iso transformer. Normally that is done as a requirement of the power supply and for safety? Most switchers I think have them on board so external ones aren't needed. If it's there as some sort of medical equipment requirement to protect the hospital electrical system from noise or something that's great if I can shed it.

Last night I was looking around a bit and I see things like the Neslab CFM-33 chiller, which if it has a pump something like that could take the place of all the water handling in the 'scope, but with non-conductive water.

I have owned a 3 phase argon in the past (6 watt SP 2011, that I actually sold on here to a fella out of PA.) I do realize this is a special dangerous beast!

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My first use is basically a static shot into the sky during an event I help run, and I've already talked to the FAA trying to figure out if

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This statement is VERY significant. You really need to spend some quality time discussing your plans with Jon before going any further. REALLY! The fact that this laser is 50x as powerful as the most powerful laser pointers and 7x as powerful as your argon is not as significant as the Q switching. Each of these short (300 nsec pulses) packs 10-20 K Watt and it explodes things like optics and retinal blood vessels.

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Originally Posted by telmnstr

...Interesting regarding the 1:1 iso transformer. Normally that is done as a requirement of the power supply and for safety? Most switchers I think have them on board so external ones aren't needed. If it's there as some sort of medical equipment requirement to protect the hospital electrical system from noise or something that's great if I can shed it...

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Careful! If your ALE lamp supply's cable shield is grounded to the box with the strain relief, be sure to isolate cable shield from the strain relief/chassis ground or you WILL blow up the ALE when you eliminate the isolation transformer and try to power it up.
Attachment 38802

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Originally Posted by Photonbeam

Careful! If your ALE lamp supply's cable shield is grounded to the box with the strain relief, be sure to isolate cable shield from the strain relief/chassis ground or you WILL blow up the ALE when you eliminate the isolation transformer and try to power it up.
Attachment 38802

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Crazy! Thanks for the heads up on that! That is the kind of stuff that I was thinking would creep up as an issue when removing the 1:1. That seems kind of sketchy.

My unit is actually in a different state from me at the moment (it's in a warehouse with a group I'm involved in up in the DC area) and I haven't brought it down to Southeastern Virginia yet so I haven't inspected it much past a few minutes :-/

@planters - oh I'll definitely continue to do research on it and talk to Jon beforehand. I'm a ways away from powering it up.

Believe me on this. The internal software is needed until you have mastered 'scope diagnostics. Do NOT modify the cooling system, keeping the rod at a constant temperature is very important for thermal lensing.

FAA wants a variance. Even todays "meh!" CDRH is going to look long and hard at issuing a varience for a 'scope only user. Especially in the DC Aerospace area.

These drill anodized aluminum. They etch uncoated metal, which blows back crud on the optics and kills the laser. It is a very high peak power system. Just finding a good beam dump can be problematic.

Very little in Allen's on-line manuals is useful. The manual is set up to meet the bare minimum FDA requirements that require enough data for an end user to theoretically be able to maintain the unit. In reality medical manufacturers are not inclined nor required to put everything you need to know in the basic service manual. I spent a year working for a medical equipment manufacturer, and the regulatory system really requires you to attend a factory course for a reason. You follow the exactly the steps in the Lscope manual, you will probably end up at a dead end. You will find yourself making phone calls to find out why the system just shut down. That is done for safety reasons industry wide.

Allen was/is showing poor judgement and mental illness in his attitude and safety practices with regard to these units. So rule him out for advice.

Tuning it correctly requires two very good power meters. One sensitive one and one brute force one. Both are in use at the same time. Advanced users can get by with one really good LPM, but that comes with some risks.

Beware of the modified so called "service" firmware that is floating around for these things for show use. It has a serious safety glitch in it. The one ON-LINE mods schematic is down right flawed. On some models it will kill the doubling crystal very quickly from lack of giant pulse supression.

Going from "NO PEAK POWER" CW lasers to one of these is awakening in how little one knows. As a service engineer, I teach pulsed laser users on a daily basis in the nanosecond and and picosecond regimes. Just knowing when you can remove the safety glasses requires serious effort, thinking, and measurements. The precautions required need a great deal of discipline. I'm good at what I do, however, My employer does not like some of my lasershow habits, with regards to beam viewing, and he has a point. Just because I do it intrensically and instinctively does not mean some one who is watching me will do it correctly down the road.

You need room, you need power, you need beam dumps and goggles and fire extinguishers, , you need tooling, You need spare lamps, crystals, and spare mirrors, and you need training on the system. Anything else is an invitation to disaster, or a lot of expensive repair parts. In the field, you need a trained assistant or two, you should not work on these alone. In the field, when working at these power levels, I either kick everyone out of the room, or EVERY move is discussed and briefed beforehand.

Please don't point me to all these youtube videos where unskilled people have not followed that route. Those systems are coasting along based on their inherent design stability. Which degrades even when setting still, inoperative.

Your already dreaming of modifying this system when you have no idea how it works, and that is a BAD thing.

I'm not going to teach this over the phone. It is mentally intensive and dangerous. You need to hire Jon.

The Per'fesser's services for pulsed laser show lasers are 1500$ weekend plus airfare, plus you have to attend one of the three or four one day laser safety courses I approve of, before hand. Ie Greg Makhov, Casey Stack, Rockwell, or James in England. Plus waver of liability. There is also an evaluation of you as a reponsible person. For CW I come out for 1/3rd of that,(or often just to make friends) so that should tell you this is not a light undertaking.

I'll see if I can find a decent on line safety manual for you, but beware, this thing bites. If you do not have glasses on and you accidently view a terminated spot from even say 20 feet, the afterimages are massive, painful, debilitating, and can last for hours, if you do not do damage. NOT A TOY!



Steve

Make certain to listen to these gentlemen (and Pat-Laserman532 too, if he chimes in)very carefully. They know what they are talking about, they have been there and done that. They will not BS you, but at the same time, you will not get spoon-fed either. Allen's site is not a good place for proper info.

I would highly recommend proper LS safety glasses, but don't let the glasses/goggles make you complacent. A reflection from the inside surface of the glasses can blind you.

And *NO* the open sky is not suitable beam termination (especially in the USA).

I'll reiterate what they said: these are not toys.

^^ Everything Steve said, with two exclamation points.

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Originally Posted by telmnstr

...They said all they need is the form.

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Heh - that 'reply' is an inch-wide and a mile deep.. First, it's not 'also need to get a Variance' - without a valid-Variance, in place, already, they won't even consider the 7140 app - you will be denied-permission, before getting to first-base. (...Not a really-great way to 'get your relationship started' with the FAA, btw.. )

Second, speaking of 'relationship', yes - the FAA 'knows these systems', and knows them well.. They (also) may not approve this - simply because - you have no prior-history of successful-filings with them.. and asking to shoot a static-beam into their airspace with The Big Bad Green Monster is your first?? Mmmyeah, I'm not the FAA, but.. I'm gotta go with 'declined', sorry to opin.

..Anyhoo, not tryin to 'kick you in las pelotas', :) be some d-bag 'laser cop', but.. You need to know - unequivocally - if you want *any* 'help' with this whole process / path to-success, it's going to-be 'conditional'... And first-up - gotta resist subscribing to the whole 'I JUST GOT A DICK-UPGRADE!!!' attitude-thing that so-many guys seem to latch onto, when buying these off Fleabay, etc... Owning / converting / operating a former-surgical KTP system - *especially* - in any-sort of public-setting, requires a very-serious / astute attitude, methodical-approach to the training / homework necessary, and.. baby-steps. '..For my first-trick, I am going to shoot a beam into airspace' is not that 'best-practices' / baby-steps approach, dig? :)

Hire the P'Fessor, or, we can talk later in the year.. I've got several-people in line ahead of ya, and they must come first... :cool: But, as with the others, your 'patience will be amply-rewarded' / pay-off, when everything works, works-well, and you don't melt eyeballs / down-planes, etc... :)

Attachment 38864Attachment 38865, http://www.photonlexicon.com/forums/...161#post262161 blah, blah, blah...

cheers!
j

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Originally Posted by dsli_jon

Attachment 38864Attachment 38865


j

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YAG Tease.

:P .

Let me explain one thing. That post may have came off as a bit snooty. The 1500$ is the price so my boss will let me deviate from the company flight/service schedule. He views me as a fragile, but needed asset. I'm not allowed to waste my time. I'm on the road for five to seven days at a time, and I only get about a day and a half for turnaround and exercise. I have a exemption in my contract for show lasers, but he needs to know where I'm at. I'm on call. This might seem restrictive. In fact it is. I might have to jet across country on a few hours notice. But I need certain benefits from this job, and I can no longer survive on glorified grad student wages.

So I'll give you a hint to make up for my tone.

When you do get it, if you get into the service screen, one very frustrating thing will catch you, zeros are actually ones. The inputs from the interlocks and functions are active low, there is a technical reason for this, noise rejection. I don't think you will find that any where on the net. A common cry is "my motherboard must be dead, I have ten zeros and three ones". That is not the case. I picked up the phone the minute I saw zeros, long, long, ago. The response on the other end, was Why did you not check everything electrical, moving, switched, and wet before calling ?." That gentleman had a point. You cannot assume. Well the ones are the issues and the zeros are valid conditional states. A few milliseconds after all those zeros appear, the unit is very dangerous internally.

Hint two: Don't peak the green power without checking everything else in the cavity first. Doubling Crystals (In ANY pulsed laser) do not survive long pulses well. In fact they like short pulses, otherwise they get thermal damage on the surface. It is the inverse of what you would think. There is a reason CW mode is in the low lamp regime.


Steve

@dsli_jon:

Yep, I know the equipment needs to have a variance. I'm not sure how much the local FAA director knows about laser shows actually. Most of the activity of the sort here comes from NASA Langley. Other than that, there aren't many shows around here generally. I can't think of ever seeing one with sky beam termination. The first I ever heard of an application was the one a few blocks from my house (multiple 40 watt RGB) but that was at angle and I'm pretty certain in the actual flight path.


I was already looking into using ADS-B to RX the GPS coords of any aircraft but unfortunately not all are pushing location and small craft don't always have those transponders :-(


I gotcha.

The funny thing is yeaaaars ago I owned a Quantel? Quantronix? YAG but I dumped it as no KTP and I wasn't really into marking/cutting then.

I'm not in a huge rush at all. The (unpaid) event I'm helping with is early next year. In the meantime I'm trying to get my RGB projector up to snuff and want to crank out some LSX shows!!!!

I was reading the manual and looking at the schematics (trying to figure out why the iso issue) and noticed that on 1Ø @ 220/240/whatever there is a power drop of some sort. I know the 40-50 watt numbers are pushing it hard, but I'm assuming at lower input power it will probably do 20-25 watts qswitched? I can only assume pushing it hard tears up the lamp quicker as well.

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Originally Posted by mixedgas

Let me explain one thing. That post may have came off as a bit snooty. The 1500$ is the price so my boss will let ...

Steve

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Heya no worries. I know how it goes. I think my employer is $170,000+ behind in salary to me and missed another paycheck fairly recently. I said if they did that, resume was going out. It went out a few places and now phone interview next week (I think) with a .com in Northern Virginia. Combined with a few needy hobbies (a/v/music stuff/lasers, pinball machines, scuba diving, etc.) times are a bit tight. But $400 laser scopes FOR THE WIN! Like, you know life is unbalanced when rent for a standard apartment is 3 x 40 watt YAG LASERS a month. You know? I still think it would be cheaper to build houses out of flat panel TVs than wood. But that is for another discussion.

Well the zeros aren't actually ones, it's just that 1s are open interlocks :-)

If the screen said "Laser will fire when all lines are low" or zero or whatever, that would be much better design.

I still need to read up on all of the alignment stuff. When I had the "large frame" argon, every time it was moved it generally had to be re-aligned. Sometimes if it just sat, it had to be re-aligned. Not the case with the 60x, of course. I'm hoping the solid state stuff isn't as bad.

Also, I would hope that it can be all peaked for highest output power with the power down low. Set it up with it low, peak it all, close it up, run the power up?

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"Also, I would hope that it can be all peaked for highest output power with the power down low. Set it up with it low, peak it all, close it up, run the power up? "

End Quote.

Nope. Not at these rep rates. That is a sure path to crystal death. Part of the design is that the 1064 passing through the crystal heats the crystal for stability. There is an oven, but tuning and performance interact differently then the simple, nearly linear, ion system. Laserscope varies the power using extracavity optics. There are high and low lamp settings, and high and low RF. A CW mode is available, but you do not peak the crystal in CW.

You need to do the two power meter alignment technique, and at some moderately high level.

Since your in the Foggy Bottom area, the former national malarial swamp, you need to store the laser in a dry place, for the sake of the optics. Not the less then climate controlled garage. Humidity and condensation attracts dust to the internals. The products I service have the crystals heaters on 24-7. and heaters in the baseplate. We use the more sensitive KD*P, but the concept is the same. A clean, dry, dust free KTP is essential. LASERSCOPE does not use the offline heater concept, so dry storage is a very good idea.

We are trying to tell you that using these is a art form. It needs inspected internally before you fire it up, a dust bunny in the wrong place is very costly. Depending on the model, You may find you need a bar coded or EEPROM based service fiber just to get going. Other units have a few selected resistors mounted in the fiber plug. Its not a easy bypass if any of the interlocked fibers are used. Not all laserscopes use them.

For example, you can't really ever clean the ends of the crystal, you use a puffer (not canned gas or methanol) to remove the dust.

Ion lasers are so tolerant compared to large YAG. Once set up correctly, they work well, but the key word here is correctly.

Any further technical discussion of the device is in PMs or by phone, following the forum's "Laserscope rule"


Steve

I can vouch for the need to align the optics for the power level you intend to run. Within reason, the general alignment that wont explode anything is still likely to be less than optimal for PO at any given lamp current setting. I have seen an improvement of 30% within this narrow range. This is because the lamp causes thermal distortions in the rod that change as the current increases and the cavity optics can be adjusted to counter some of this distortion and improve output power.